It's really good that you are sober for this. I know it's really difficult, but it will be far far worse if one or both of you starts drinking again. It's a horrible addiction and I hope your husband will be able to get enough medical care to give him time to have some options. The GI guy is your best bet, like they told you when he was discharged. The only way treatment will have any chance of working is if there is no alcohol at all.
I'm very sorry you're going through this - just know that your own sobriety will help you to feel better in general in time, and it may save your life. Tough lesson to learn, no doubt. ((Hug))
Are you going back to the ER today?